The invention relates to a method for the preparation of a chip card for electronic signature services. In particular the invention relates to the preparation of subscriber identification cards, so-called SIM cards, for electronic signature services via mobile communications.
In the case of an electronic signature it is a matter of electronic data which are supposed to ensure the authenticity and integrity of electronic information, usually electronic documents. In addition an electronic signature is supposed to guarantee the identity of the person signing. These features in turn should be verifiable with the help of the electronic signature. With these properties the electronic signature should constitute the electronic equivalent of the genuine signature. These strived for properties of the electronic signature are achieved depending on the applied signature technology, existing usage scenario, as well as the given legal situation.
An electronic signature is usually based on asymmetric encryption methods. The known public key of a signer allows the verification of his signature, which was generated with his private key. In contrast to qualified signatures however in the case of advanced signatures, private and public keys do not have to be associated to the signature creator. Hence while the authenticity and integrity of the signed data can be verified, however an identification of the signer via a certificate is not possible. In this case for example biometric methods, such as e.g. the genuine signature, which is recorded during the signing and embedded in the document in an encoded manner, can contribute to identification.
For the purpose of backing up the biometric data said data are additionally included in the hash value (checksum). In the case of signature verification then along with the signed data also the authenticity and integrity of the identification feature is checked.
For the identification of the signer and release of the signature service for example a PIN (personal identification number) is used. This PIN is up to now generated by a service provider, uniquely associated to a user (personalized) and communicated to the user together with the signature key via a communication route, for example by letter. In the case of this method the danger exists that a third party can misuse the data discovering the signature data and the PIN and can then pass as the signer. Additionally, as a rule an expenditure that is not inconsiderable is generated by the generation of the PIN.